Drug delivery implants

ABSTRACT

An orthopedic implant system includes an external fixation device implantable at a selected location within a corporeal body and configured for delivering at least one therapeutic agent to the corporeal body. The external fixation device includes an implantable pin, a sheath coupled with the pin, a reservoir coupled with the sheath and a plurality of channels. The pin defines the plurality of channels. The reservoir is configured for receiving the at least one therapeutic agent. The plurality of channels are configured for conveying the at least one therapeutic agent from the reservoir to a treatment site relative to the corporeal body.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of U.S. patent application Ser. No. 12/540,676,entitled “DRUG DELIVERY IMPLANTS,” filed Aug. 13, 2009, which isincorporated herein by reference. U.S. patent application Ser. No.12/540,676 is a non-provisional application based upon U.S. ProvisionalPatent Application Ser. No. 61/088,379, entitled “DRUG DELIVERYIMPLANTS,” filed Aug. 13, 2008, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to implants, and, more particularly, toorthopaedic implants.

2. Description of the Related Art

Orthopaedic implants include short-term implants, long-term implants,and non-permanent implants. Short-term implants include implants for thetreatment of infection. Long-term implants include total implants fortotal hip, knee, shoulder, and elbow joints. Non-permanent implantsinclude trauma products such as nails, plates, and external fixationdevices.

Regarding short-term implants, when tissue, especially bone, surroundingan orthopaedic implant becomes infected, that implant must typically beremoved, the infection must be eliminated, and a new implant (revisionimplant) is then implanted. The span of time between implant removal andrevision implantation can be from several weeks (about 4 weeks) to a fewmonths (approximately 3 months). During this time surgeons currentlyhave two basic options: create temporary implants during surgery withantibiotic bone cement (created with or without the aid of a mold) oruse a preformed antibiotic bone cement temporary implant (e.g.Exactech's InterSpace™ Hip and Knee). In either case, antibiotic bonecement is used to deliver antibiotics directly to the site of theinfection in the bone. The patient also typically receives IVantibiotics. The shortcomings of such implants are the limited durationin which they deliver a clinically relevant dose of antibiotics, thelack of ability to change antibiotic type or dose during the 4-12 weektreatment time, and the limited patient mobility, range of motion, andweight bearing that they allow.

Further, antibiotic cements typically provide useful local antibioticlevels for a duration of less than one week. The treatment time isfrequently 6 to 8 weeks. However, beyond one week, the antibiotic cementimplants provide no useful amount of antibiotics.

Further, infections can be caused by a great number of bacteria,viruses, yeast, etc. The effectiveness of various antibiotics dependsgreatly upon what in particular has caused the infection. Thus, in orderto treat an infection most effectively, the cause of that infection mustbe known. The results of cell cultures give this information andindicate which antibiotic and dose will most effectively treat theinfection. The samples for culturing are usually collected duringsurgery. The results of the culture are not known until several daysafter the surgery. Since the type of antibiotic cement used in currenttemporary implants must be chosen at or before the time of surgery, theinformation gained from the cultures cannot be applied to theantibiotics used at the infection site.

Further, one key to a patient recovering from joint surgery with fullrange of motion in that joint is to encourage movement of that joint.This helps to prevent the formation of scar tissue and stiffening oftissue around the joint. The current options for temporary implantsallow limited range of motion and weight bearing at best.

Regarding long-term implants, with regard to bone ingrowth, boneingrowth into a porous material is sometimes required to providestability or fixation of an implant to the bone. Examples of thisinclude porous coatings on total joint components, fusion devices (i.e.,spinal fusion devices), and bone augmentation components (i.e., tibialwedges).

With regard to resorbtion, resorbtion can occur in the regionsurrounding a total joint implant for a number of reasons and can leadto implant loosening and subsequent revision surgery. Some causes ofresorbtion include:

-   -   Stress shielding—Bone tissue requires loading to remain strong        and healthy. If an implant does not properly transfer loads to        the surrounding bone, regions of bone can resorb.    -   Lysis due to wear particles—Osteolysis and resorbtion are        frequently caused by the body's reaction to wear particles        created by the bearing of one total joint component on another.    -   Osteoporosis or other bone disorders—bone metabolic disorders        can also cause the resorbtion of bone.

With regard to oncology, localized delivery of oncological drugs in theregion of tumors may improve results in slowing/halting tumor growth.The ability for localized delivery may also lessen the need/dose ofsystemic drugs, resulting in fewer side effects.

Regarding non-permanent implants (i.e., trauma implants), suchnon-permanent implants include nails, plates, and external fixationdevices. Nails are temporary, intramedullary devices. They are typicallyused to treat traumatic fracture. The risk of infection can be highespecially in the case of open fractures. With regard to oncology, nailscan be used to treat fractures associated with bone tumors. They canalso be used to help prevent a fracture where cancer has weakened bone.Plates treat many of the same indications as nails; however plates areapplied to the outside of the bone. External fixation devices are atemporary implant that is used to stabilize a fracture. These can beused for days to months. External fixation devices typically includeseveral pins fixed in the bone and extending through the skin to a rigidplate, ring, rod, or similar stabilizing device. These devices carry theadded risk of infection due to their extending through the skin.Bacteria can travel along the pins directly to the soft tissue and bone.

What is needed in the art is an orthopaedic implant which includes areservoir and a plurality of channels leading from the reservoir todeliver at least one therapeutic agent locally to bone or surroundingsoft tissue.

SUMMARY OF THE INVENTION

The present invention provides an orthopaedic implant which includes areservoir and a plurality of channels leading from the reservoir todeliver at least one therapeutic agent locally to bone or surroundingsoft tissue.

The invention in one form is directed to an orthopaedic implant system,including an orthopaedic implant implantable at a selected locationwithin a corporeal body and configured for delivering at least onetherapeutic agent to the corporeal body. The implant includes areservoir and a plurality of channels. The reservoir is configured forreceiving the at least one therapeutic agent. The plurality of channelsare configured for conveying the at least one therapeutic agent from thereservoir to a treatment site relative to the corporeal body.

The invention in another form is directed to a method of using anorthopaedic implant system, the method including the steps of:implanting an orthopaedic implant at a selected location within acorporeal body, the implant including a reservoir and a plurality ofchannels; receiving at least one therapeutic agent in the reservoir;conveying the at least one therapeutic agent from the reservoir to atreatment site relative to the corporeal body via the plurality ofchannels; and delivering the at least one therapeutic agent to thecorporeal body.

The invention in yet another form is directed to an orthopaedic implantsystem including an orthopaedic implant and a porous surface. Theorthopaedic implant includes a body implantable at a selected locationwithin a corporeal body and which is configured for delivering atherapeutic agent to the corporeal body. The body includes an exteriorsurface defining a plurality of surface channels and having an absenceof a therapeutic agent reservoir. The plurality of surface channels areconfigured for receiving, holding, delivering, and being refilled withthe therapeutic agent after the implant has been implanted in thecorporeal body. The porous surface is attached to the exterior surface.The porous surface is configured for receiving at least one of bone andtissue ingrowth therein and includes a first side attached to theexterior surface and a second side opposing the first side. The poroussurface includes a plurality of through-holes running from the firstside to the second side. The plurality of surface channels communicateand cooperate with the plurality of through-holes to provide thetherapeutic agent from the plurality of surface channels to the firstside of the porous surface and to the second side of the porous surface.

An advantage of the present invention is that it provides an orthopaedicimplant that allows for the delivery of drugs directly to the bone.

Another advantage of the present invention is that it provides atemporary or short-term implant that would allow for the delivery ofantibiotics directly to the bone and surrounding tissue.

Yet another advantage of the present invention is that it would allowfor post-operative injections of antibiotics into the implant, therebyallowing for the delivery of multiple antibiotics throughout treatment.

Yet another advantage of the present invention is that the implantaccording to the present invention allows for the delivery of thecorrect dose of antibiotics, continuously for any length of timerequired.

Yet another advantage of the present invention is that is provides anorthopaedic implant which can deliver a therapeutic agent locally tobone or surrounding soft tissue as long as the implant remains implantedin a corporeal body.

Yet another advantage of the present invention is that it provides along-term implant which would allow drugs to be delivered directly tothe bone and surrounding tissue (or to any specific location).

Yet another advantage of the present invention is that, with regard toenhancing bone ingrowth and combating resorbtion, it provides that bonegrowth stimulators can be injected intraoperatively or postoperativelyto enhance or speed bone ingrowth into porous material (i.e., porouscoatings on total joint components; fusion devices, i.e., spinal fusiondevices; bone augmentation components, i.e., tibial wedges); these drugscould also be injected months to years post-operatively, using animplant according to the present invention, to combat bone resorbtiondue to such causes as stress-shielding, osteolysis, or bone metabolicdisorders.

Yet another advantage of the present invention is that, with regard tooncology, the present invention provides an implant that would similarlyallow for delivery of drugs to some or all tissue surrounding theimplant.

Yet another advantage of the present invention is that it would allowantibiotics to be delivered to the bone surrounding the nail of thepresent invention as a preventative or to treat an infection if onedevelops.

Yet another advantage of the present invention is that it provides anon-permanent implant, such as a nail according to the presentinvention, which can provide the delivery of bone growth stimulatorsdirectly to the region of bone fracture(s); such delivery of bone growthstimulators can be advantageous in difficult cases such as non-unions,bony defects, and osteotomies.

Yet another advantage of the present invention is that it provides anon-permanent implant, such as a nail according to the presentinvention, which can provide localized delivery of oncological drugs inthe region of tumors which may improve results in slowing/halting tumorgrowth; this ability for localized delivery provided by the presentinvention may also lessen the need/dose of systemic drugs, resulting infewer side effects.

Yet another advantage of the present invention is that it provides anexternal fixation device that would allow antibiotics or otheranti-infective agents to be provided to the bone and soft tissuesurrounding the pins.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a schematic representation of a sectional view of a short-termfemoral hip implant according to the present invention;

FIG. 2 is a schematic representation of a sectional view of a short-termfemoral hip implant system according to the present invention;

FIG. 3 is a schematic representation of a sectional view of a short-termacetabular cup implant according to the present invention;

FIG. 4 is a schematic representation of a top view of a short-termfemoral knee implant according to the present invention;

FIG. 5 is a schematic representation of a sectional view of theshort-term femoral knee implant taken along line 5-5 in FIG. 4;

FIG. 6 is a schematic representation of a top view of a short-termfemoral knee implant according to the present invention;

FIG. 7 is a schematic representation of a front view of short-termfemoral knee implant;

FIG. 8 is a schematic representation of a sectional view of a short-termtibial knee implant;

FIG. 9 is a schematic representation of a side view of a long-termfemoral hip implant system according to the present invention;

FIG. 10 is a schematic representation of a sectional view of thelong-term femoral hip implant of FIG. 9;

FIG. 11 is a schematic representation of a top view of a long-termfemoral knee implant according to the present invention;

FIG. 12 is a schematic representation of a sectional view of thelong-term femoral knee implant taken along line 12-12 in FIG. 11;

FIG. 13 is a schematic representation of a top view of a long-termfemoral knee implant system according to the present invention;

FIG. 14 is a schematic representation of a side view of a long-termfemoral knee implant system according to the present invention, thelong-term femoral implant being attached to a femur;

FIG. 15 is a schematic representation of a side view of a long-termfemoral hip implant system according to the present invention;

FIG. 16 is a schematic representation of a sectional view of thelong-term femoral hip implant system of FIG. 15 taken along line 16-16;

FIG. 17 is a schematic representation of a sectional view of anorthopaedic nail according to the present invention;

FIG. 18 is a schematic representation of a sectional view of anorthopaedic plate according to the present invention;

FIG. 19 is a schematic representation of a sectional view of an externalfixation device according to the present invention;

FIG. 20 is a schematic representation of a sectional view of anorthopaedic implant system including a therapeutic agent cartridge;

FIG. 21 is a schematic representation of a sectional view of anorthopaedic implant of FIG. 20 without the therapeutic agent cartridgeinserted therein;

FIG. 22 is a schematic representation of a side view of an orthopaedicimplant that is entirely porous;

FIG. 23 is a schematic representation of a side view of an orthopaedicimplant that is entirely porous and includes a reservoir and drugdelivery channels according to the present invention;

FIG. 24 is a schematic representation of a sectional view of anorthopaedic implant that is partially porous;

FIG. 25 is a schematic representation of a sectional view of anorthopaedic implant that is partially porous and includes a reservoirand drug delivery channels according to the present invention;

FIG. 26 is a schematic representation of a sectional view of anorthopaedic implant that is partially porous and includes a reservoirand drug delivery channels according to the present invention;

FIG. 27 is a schematic representation of a sectional view of anorthopaedic implant system according to the present invention includinga sponge-like material;

FIG. 28 is a schematic representation of an orthopaedic implant systemaccording to the present invention; and

FIG. 29 is a schematic representation of an orthopaedic implant systemaccording to the present invention.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate embodiments of the invention, and such exemplifications arenot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly to FIG. 1, there isshown an orthopaedic implant system 30 according to the presentinvention which generally includes an orthopaedic implant 32 implantableat a selected location within a corporeal body 34 and configured fordelivering at least one therapeutic agent 36 to the corporeal body 34.The implant 32 includes at least one reservoir 38 and a plurality ofchannels 40. The reservoir 38 is configured for receiving at least onetherapeutic agent 36 and can be configured for being refilled with thetherapeutic 36 agent after the implant 32 has been implanted in thecorporeal body 34. Channels 40 form pathways for the therapeutic agent36 to move from the reservoir 38 to a treatment site 42 relative to thecorporeal body 34. Each pathway formed by a channel 40 is an interiorspace formed by the walls of channel 40. Channel 40 can, for example,have a circular, square, or some other cross-sectional shape. Thus,channels 40 are configured for conveying at least one therapeutic agent36 from reservoir 38 to treatment site 42 relative to corporeal body 34.

FIG. 1 shows two reservoirs 38 and a plurality of channels 40 runningfrom each reservoir 38. The implant according to the present invention(i.e., implant 232) may include only one reservoir (i.e., reservoir238). The reservoirs 38 of FIG. 1 can optionally hold differenttherapeutic agents 36 at the same time; stated another way, eachreservoir 38 can hold a different therapeutic agent 36, or eachreservoir 38 can hold at least two therapeutic agents 36. Thus, theimplant according to the present invention is configured for deliveringa plurality of therapeutic agents to the corporeal body via thereservoir and the plurality of channels; examples of such implantsinclude implant 32 (FIG. 1) and implant 232 (FIG. 3). Further, implant32 may be formed such that no seal or seal cap is formed over any ofchannels 40 prior to release of any therapeutic agent 36.

A corporeal body herein means the physical body of a human being or ofan animal (i.e., a veterinary patient). Thus, a corporeal body is one offlesh and bones. The corporeal body can be alive or dead. The corporealbody can also be referred to as a patient body herein, which includesboth human and veterinary “patients”, alive or dead. Therapeutic agentscan also be referred to herein as drugs or medicinal agents. Therapeuticagents can be formed, for example, as a liquid, a solid, a capsule, or abead.

Further, FIG. 1 shows that implant 32 includes a body 44 implantable atthe selected location. Body 44 defines reservoir 38 and channels 40 andincludes an exterior surface 46. The reservoir of the present inventioncan be a cavity or an enclosed pocket (closed but for channels extendingto the surface of the body of the implant) formed by the body of theimplant. The reservoir can be formed by the core (i.e., the centralinterior portion) of the body, rather than in the exterior surface ofthe body. The reservoir can occupy a substantial portion of the core butyet still have elongate channels running from the reservoir to theexterior surface. Reservoir 38 is a cavity in body 44. Reservoir 38 isnot a through-hole through body 44. Channels 40 fluidly communicatereservoir 38 with exterior surface 46 and thereby forms the pathways forthe at least one therapeutic agent 36 to move from reservoir 38 toexterior surface 46. That is, channels 40 fluidly communicate reservoir38 with exterior surface 46 and thereby convey at least one therapeuticagent 36 from reservoir 38 to exterior surface 46. FIG. 1 shows the body44 of the implant 32 being the implant 32 itself.

Further, FIG. 1 shows that implant 32 is formed as a hip prosthesis andthat corporeal body 34 is formed as a hip. More specifically, FIG. 1shows a sectional view of a short-term femoral hip implant 32 (which isone type of orthopaedic implant) which forms part of the upper femur(or, thighbone) and is thus load-bearing. The body 44 of the femoral hipprosthesis 32 of FIG. 1 (the body 44 and the femoral hip prosthesis 32being coextensive relative to one another and thus being the samestructural member in FIG. 1) includes a stem (the downward extendingportion of implant 32 in FIG. 1) which can be inserted into the upperfemur of a body 34 and a femoral head (the ball portion of implant 32 inFIG. 1) which is received by and mates with an acetabulum (i.e., thepatient's natural acetabulum, or a prosthetic acetabular cup). FIG. 1shows that both the stem and the femoral head include reservoirs 38 anda plurality of channels 40 running from the respective reservoirs 38 tothe exterior surface 46 of the implant 32. Depending upon the size ofreservoir 38 relative to exterior surface 46 and/or the nearness ofreservoir 38 to exterior surface 46, channels 40 can be formed as holesor apertures in body 44. In use, therapeutic agent 36 is inserted inreservoirs 38 prior to and/or after implantation of implant in body 34.Therapeutic agent 36 can then migrate into channels 40 and travel viachannels 40 to exterior surface 46 (channels 40 forming holes inexterior surface 46). Therapeutic agent 36 exits channels 40 andcontacts treatment site 42, which can be for example bone or tissue.

The orthopaedic implant of the present invention can be a prosthesis, anail, a plate, or an external fixation device formed as an implantablepin. FIGS. 1-16 and 20-27 shows orthopaedic implants which areprostheses. A prosthesis is an implant that substitutes for orsupplements a missing or defective part of the corporeal body. FIG. 17shows an orthopaedic implant which is a nail. FIG. 18 shows anorthopaedic implant which is a plate. FIG. 19 shows an orthopaedicimplant which is an external fixation device with an implantable pin.

FIG. 2 shows another embodiment of the orthopaedic implant according tothe present invention. Structural features in FIG. 2 corresponding tosimilar features in FIG. 1 have reference characters raised by amultiple of 100. Short-term orthopaedic implant system 130 includes ashort-term prosthetic implant 132 and an attachment feature 150. Body144 defines reservoir 138 and channels 140 running from reservoir 138 toexterior surface 146. Attachment feature 150 is for attaching a port(not shown in FIG. 2) thereto. The attachment feature 150 can be atubular element. The attachment feature 150 and the port can be used torefill the reservoir 138 with a therapeutic agent. Upon fillingreservoir 138 with the therapeutic agent (either initially and/or as arefill) via attachment feature 150, the therapeutic agent can move fromthe reservoir 138 to the treatment site via channels 140.

FIG. 3 shows another embodiment of the orthopaedic implant according tothe present invention. Structural features in FIG. 3 corresponding tosimilar features in prior figures have reference characters raised by amultiple of 100. FIG. 3 shows a sectional view of another short-term hipimplant 232. Prosthetic implant 232 is formed as an acetabular cup,which receives a femoral head. The body 244 of the acetabular cup 232 isthe acetabular cup 232 in FIG. 3. Body 244 defines reservoir 238 and aplurality of channels 240 running from reservoir 238 to exterior surface246. Upon filling reservoir 238 with the therapeutic agent (eitherinitially and/or as a refill), the therapeutic agent moves from thereservoir 238 to the treatment site via channels 240.

FIGS. 4-8 show additional embodiments of orthopaedic implants accordingto the present invention. More specifically, FIGS. 4-8 show short-termorthopaedic implants formed as prosthetic knee implants, both femoraland tibial prosthetic knee implants. Structural features in FIGS. 4-7corresponding to similar features in prior figures have referencecharacters raised by a multiple of 100. FIGS. 4 and 5 show that the body344 of implant 332 is the femoral knee implant 332. Body 344 includes alower portion (the generally U-shaped piece in FIG. 5) and an optionalstem (the vertical, upstanding piece atop the lower portion in FIG. 5).Both the lower portion and the stem include drug reservoirs 338 and drugdelivery channels/holes 340 communicating the respective reservoir 338with exterior surface 346 to deliver the therapeutic agent(s) in thereservoirs 338 to the treatment site(s) 342. FIG. 6 shows a top view offemoral knee implant 432 similar to the implant 332 shown in FIG. 5.Channels 440 are shown as exit holes in exterior surface 446 of thelower portion. The circle in FIG. 6 represents an optional, upstandingstem 452. FIG. 7 shows a front view of short-term femoral knee implant532 marked with lettering which is more radiopaque than the implant body544 so that the letters are visible on an X-ray or fluoroscope, as shownin FIG. 7. Upon filling the reservoirs for FIGS. 5 and 6 with thetherapeutic agent (either initially and/or as a refill), the therapeuticagent can move from these reservoirs to the treatment site via channels340, 440.

FIG. 8 shows a sectional view of a short-term tibial knee implant 632according to the present invention. Structural features in FIG. 8corresponding to similar features in prior figures have referencecharacters raised by a multiple of 100. The body 644 of implant 632 isthe tibial knee implant 632. Body 644 includes a tibial tray (thegenerally horizontal piece in FIG. 8) and an optional stem (thegenerally vertical piece below the horizontal piece in FIG. 8). Both thelower portion and the stem define drug reservoirs 638 and drug deliverychannels/holes 640 communicating the respective reservoir 638 withexterior surface 646 to deliver the therapeutic agent(s) to thetreatment site(s) 642. Upon filling reservoir 638 with the therapeuticagent (either initially and/or as a refill), the therapeutic agent canmove from the reservoir 638 to the treatment site 642 via channels 640.

The implants according to the present invention shown in FIGS. 1-8 arethus short-term implants that can be used, for example, to treatinfections within a corporeal body. Such short-term or temporaryimplants allow for the delivery of therapeutic agents, such asantibiotics, directly to the bone of a corporeal body and to surroundingtissue.

A device such as a port could be used to allow for post-operativeinjections of antibiotics into the implant. (See FIG. 2). This wouldallow for the delivery of multiple antibiotics throughout treatment.Reservoirs and/or channels in the implant would allow the antibioticsfrom these injections to be delivered over a time-period from hours toweeks. (FIGS. 1-8). Injection intervals of approximately a week wouldlikely be well-accepted clinically. The drugs could be delivered to allbone and soft tissue surrounding the implant or only to specificlocations. Variations of this concept would allow for a range of jointmobility from no motion at the joint to the mobility typical of apermanent total joint. These short-term implants can be held in the bonewith a loose press-fit or with antibiotic or standard bone cement. Inthe case of bone cement, cement restrictors would also be included inthe technology to prevent cement from sealing over the drug deliveryholes.

Antibiotic cements typically provide useful local antibiotic levels fora duration of less than one week. The treatment time is frequently sixto eight weeks. However, beyond one week, the antibiotic cement implantsprovide no useful amount of antibiotics. The implant according to thepresent invention, by contrast, allows the delivery of the correct doseof antibiotics continuously for any length of time required. Through afeature such as a port attached to the implant of the present invention,the implant reservoir can be refilled as often as necessary to providethe proper drug dosing.

The implant of the present invention allows for any number ofantibiotics to be used at any time during treatment. An initialantibiotic can be used at the time of surgery. If the cell culturesindicate that a different antibiotic or dose would be more effective,that change in treatment regimen can be made in accordance with thepresent invention.

A short-term femoral hip implant, as discussed above, can include a stemand a separate head or could be a one-piece construction. Multiple sizesof stem and head size could be accommodated. A separate acetabularcomponent could be provided, as discussed above. The femoral head couldmate with a short-term acetabular component or with the patient'sacetabulum. (See FIGS. 1-3). According to the present invention, drugscan be delivered to the acetabulum through the head of the femoralcomponent if an acetabular component is not used (See FIG. 1) or throughthe acetabular component if one is used (See FIG. 3).

A short term knee implant can include a one-piece tibial component(combining the two pieces of a standard total knee replacement) and aone- or two-piece femoral component (the two-piece design would combinethe condyles and stem). The present invention provides multiple sizes oftibia components and of stem and condyles (either combined as one pieceor separate). (See FIGS. 4-8). Similar components are provided forshoulder, elbow, and other joints, according to the present invention.

Since the implants of FIGS. 1-8 are designed for short-term use, theshort-term implants of the present invention can include markings whichare both visible on the implant surface by the naked eye and visible byX-ray, as indicated above. These markings would clearly indicate thatthe implants are intended for short-term use only. (See FIG. 7).

The present invention provides an orthopaedic implant system (whethershort-term, long-term, or non-permanent implants) which provide forcontinuously delivering drugs to a point near the implant or to theentire region surrounding the implant for extended periods of time. Theimplants according to the present invention shown in FIGS. 9-16 arelong-term implants. Such implants can be used, for example, as totalhip, knee, shoulder, and elbow joints within a patient body. Thelong-term implants of the present invention have a basic similarity withthe short-term implants described above. Thus, structural features inFIGS. 9-16 corresponding to similar features in prior figures havereference characters raised by multiples of 100. Thus, similar to theshort-term implants described above, the present invention furtherprovides a long-term implant which would allow drugs to be delivereddirectly to the bone and surrounding tissue (or to any specificlocation). A device such as a port could be used to allow forpost-operative injections of drugs into the long-term implant. (See FIG.14). This would allow for the delivery of any number of drugs throughouttreatment and allow for the refilling of drugs to provide proper drugdosing throughout treatment. Reservoirs and/or channels in the long-termimplant according to the present invention would allow the drugs fromthese injections to be delivered over a time period from hours to weeks.(See FIGS. 9-16). The drugs could be delivered to all bone and softtissue surrounding the implant or only to specific locations.

FIGS. 9 and 10 show a long-term femoral hip prosthetic implant system730 according to the present invention. Structural features in FIGS. 9and 10 corresponding to similar features in prior figures have referencecharacters raised by multiples of 100. System 730 includes a long-termfemoral hip prosthetic implant 732 and a porous surface 754 attached tothe exterior surface 746. Similar to the short-term implants discussedabove, implant has a body 744 defining a drug reservoir 738 and aplurality of drug delivery channels 740 running from the reservoir 738to the exterior surface 746 so as to deliver a therapeutic agent(s) to atreatment site in the corporeal body. Porous surface 754 is configuredfor receiving bone and/or tissue ingrowth therein. Such ingrowth isshown by arrow 756 in FIG. 9. The porous surface 754 can be variouslyreferred to as a porous member, a porous pad, or a scaffold. Drugdelivery channels 740 can be routed by or through body 744 so as toavoid the ingrowth region. Stated another way, channels 740 can berouted by or through body 744 so as to avoid releasing therapeuticagents into porous surface 754. By contrast, channels 740 can be routedby or through body 744 so as to release drugs through the ingrowthporous surface 754. FIG. 9 shows channels 740 which avoid releasingdrugs into porous surface 754. Upon filling reservoir 738 with thetherapeutic agent (either initially and/or as a refill), the therapeuticagent can move from the reservoir 738 to the treatment site via channels740.

FIGS. 11 and 12 show a long-term femoral knee implant according to thepresent invention. Structural features in FIGS. 11 and 12 correspondingto similar features in prior figures have reference characters raised bymultiples of 100. The body 844 of implant 832 is the femoral kneeimplant 832. Body 844 includes a lower portion (the generally U-shapedpiece in FIG. 12) and an optional stem (the vertical, upstanding pieceatop the lower portion in FIG. 12). Both the lower portion and the steminclude drug reservoirs 838. The stem further includes drug deliverychannels/holes 840 communicating the respective reservoir 838 withexterior surface 846 to deliver the therapeutic agent(s) to thetreatment site(s) 846. The lower portion also includes at least one drugdelivery channel 840 leading from reservoir to a treatment site. Uponfilling reservoir 838 with the therapeutic agent (either initiallyand/or as a refill), the therapeutic agent can move from the reservoir838 to the treatment site via channels 840.

FIG. 13 shows a long-term femoral knee implant system 930 according tothe present invention. Structural features in FIG. 13 corresponding tosimilar features in prior figures have reference characters raised bymultiples of 100. System 930 includes a prosthetic implant 932 similarto the implant 832 of FIG. 12 but with a plurality of ingrowth poroussurfaces 954 attached to the body 944 of implant 932. Each poroussurface 954 is configured for receiving bone and/or tissue ingrowththerein. Further, while the reservoir cannot be seen in FIG. 13, a drugdelivery channel 940 leading from the drug reservoir is shown in FIG.13. The reservoir of FIG. 13 can be situated just under exterior surface946 as reservoir 838 is shown in FIG. 12. Channel 940 routes around (andthereby avoids) ingrowth pads 954. Upon filling the reservoir of implant932 with the therapeutic agent (either initially and/or as a refill),the therapeutic agent can move from the reservoir of implant 932 to thetreatment site via channels 940.

FIG. 14 shows a long-term femoral knee implant system 1030 according tothe present invention. Structural features in FIG. 14 corresponding tosimilar features in prior figures have reference characters raised bymultiples of 100. System 1030 includes a prosthetic implant 1032 similarto the implant 832 of FIG. 12. Implant 1032 is attached to a femur 1035.The system 1030 further includes an attachment feature or element 1050(such as a tubular element) for an injection port 1058, an injectionport 1058, a catheter 1060, and a reservoir 1062 remote to the implant1032. The injection port is provided for additional refilling of drugsinto the implant 1032, which includes at least one channel for routingthe therapeutic agent to the treatment site. Since an external reservoir1062 is attached to implant 1032, implant body 1044 may or may notdefine an additional internal reservoir. Upon filling the internalreservoir of implant 1032 with the therapeutic agent (either initiallyand/or as a refill) via attachment element 1050, injection port 1058,catheter 1060, and external reservoir 1062, the therapeutic agent canmove from the reservoir of implant 1032 to the treatment site via thedrug delivery channels. If implant 1032 does not have an internalreservoir, then the therapeutic agent moves to the treatment site viathe drug delivery channels from external reservoir 1062 via catheter1060, injection port 1058, and attachment element 1050.

FIGS. 15 and 16 show a long-term femoral hip implant system 1130according to the present invention. Structural features in FIGS. 15 and16 corresponding to similar features in prior figures have referencecharacters raised by multiples of 100. FIG. 15 shows long-term femoralhip implant system 1130 including a long-term femoral hip prostheticimplant 1132 and an ingrowth porous surface 1154. FIG. 16 shows a firstporous surface 1154 on the top (as oriented in FIG. 16) of the implantbody 1144 or substrate 1144 (in each of the figures, the body 1144 canalso be referred to as a substrate) and a second porous surface 1154 onthe bottom (as oriented in FIG. 16) of the body 1144. Porous surfaces1154 are configured for receiving bone and/or tissue ingrowth therein,as shown by arrow 1156. While FIG. 16 shows some space between poroussurfaces 1154 and body 1144, it is understood that this space is forillustrative purposes and that porous surfaces 1154 can be flush withbody 1144 but for any adhesive that may be used to attach surfaces 1154with exterior surface 1146 of body 1144. Each porous surface 1154includes a first side 1164 attached to exterior surface 1146 of body1144 and a second side 1166 opposing said first side 1164. Each poroussurface 1154 includes a through-hole 1168 running from first side 1164to second side 1166. Through-hole 1168 is configured for communicatingthe therapeutic agent 1136 from first side 1164 to second side 1166 andthereby for communicating the therapeutic agent 1136 to the treatmentsite 1142. The through-holes 1168 in porous surfaces 1154 lead tosurface channels 1170 and sub-surface channels 1172, respectively.Channels 1170 and 1172 can function essentially the same as channels 40in that they are drug delivery channels. FIG. 16 shows a reservoir 1138and connecting channels 1140 in broken lines; for, it is understood thatsuch a reservoir 1138 and connecting channels 1140 (connecting reservoir1138 with channels 1170 and/or 1172) may not be visible in this section,or, alternatively, that such a reservoir 1138 and connecting channels1140 can be optional (stated another way, the implant 1132 would notcontain such an interior reservoir 1138 and connecting channels 1140leading from the reservoir 1138 to the surface channels 1170 or thesub-surface channels 1172).

Further, FIG. 16 shows that exterior surface 1146 of body 1144 candefine a surface channel 1170 which is in communication with andcooperates with channel 1140 and through-hole 1168 of porous surface1154 to provide the therapeutic agent 1136 from the reservoir 1138 tothe treatment site 1142. FIG. 16 shows a plurality of such surfacechannels 1170, each of which can optionally be connected to reservoir1138 via a respective connecting channel 1140, as discussed above. Ifimplant 1132 has reservoir 1138 and connecting channels 1140, then uponfilling reservoir 1138 with the therapeutic agent (either initially oras a refill), the therapeutic agent can move from reservoir 1138 to thetreatment site via the channels 1140 and 1170. If implant 1132 does nothave reservoir 1138 and connecting channels 1140, then surface channels1170 can be filled with the therapeutic agent (either initially and/oras a refill) and the therapeutic agent moves via surface channels 1170,through through-holes 1168, to the treatment site 1142. The therapeuticagent can also be provided to the bone and/or tissue growing into poroussurface 1154.

Further, FIG. 16 shows that channels 1140 running from reservoir 1138can connect to the sub-surface channels 1172. Sub-surface channels 1172and through-holes 1168 in porous surface 1154 are aligned with andcooperate with one another to provide the therapeutic agent 1136 fromthe reservoir 1138 to the treatment site 1142. Holes 1174 (which canalso be considered as channels of the present invention, like channels40) are also provided in body 1144 leading from subsurface channels 1172to exterior surface 1146. These holes 1174 can be considered to be partof the respective channels 1140 and 1172.

FIGS. 15 and 16 thus also show an orthopaedic implant system 1130including an orthopaedic implant 1132 and a porous surface 1154. Theorthopaedic implant 1132 includes a body 1144 implantable at a selectedlocation within a corporeal body 1134 and configured for delivering atherapeutic agent 1136 to corporeal body 1134. Body 1144 of implant 1132includes an exterior surface 1146 defining a plurality of surfacechannels 1170 and, as discussed above, can have an absence of atherapeutic agent reservoir 1138. The broken lines of the reservoir 1138in FIG. 16, as stated above, indicates that the reservoir 1138 isoptional. The plurality of surface channels 1170 are configured forreceiving, holding, delivering, and being refilled with the therapeuticagent 1136 after implant 1132 has been implanted in corporeal body 1134.Orthopaedic implant 1132 is a prosthesis. Alternatively, implant 1132can be formed as a nail (FIG. 17), a plate (FIG. 18), or an externalfixation device with an implantable pin (FIG. 19). Porous surface 1154is attached to exterior surface 1146. Porous surface 1154 is configuredfor receiving at least one of bone and tissue ingrowth therein, as shownby arrow 1156. As discussed above, porous surface 1154 includes a firstside 1164 attached to exterior surface 1146 and a second side 1166opposing first side 1164. Porous surface 1154 includes a plurality ofthrough-holes 1168 running from first side 1164 to second side 1166. Theplurality of surface channels 1170 communicate and cooperate with theplurality of through-holes 1168 to provide the therapeutic agent 1136from the plurality of surface channels 1170, then to first side 1164 ofporous surface 1154, and then to second side 1166 of porous surface1154. Surface channels 1170 can be filled with the therapeutic agent(either initially and/or as a refill) and the therapeutic agent 1136moves via surface channels 1170, through through-holes 1168, to thetreatment site 1142.

Thus, the present invention could be applied to long-term implants withany type of porous coating or surface or to cemented implants. Drugscould be delivered through the porous coatings or be routed to regionswithout porous coatings (as disclosed above), depending on therequirements. (See FIGS. 9, 10, 13, 15, and 16). For delivery throughthe porous coatings, channels can be created on the surface of theimplant substrate (the solid material of the implant to which the poroussurface is attached—see FIG. 14) or below the surface, as disclosedabove relative to FIGS. 15 and 16. For surface channels, holes can bedrilled through the porous surface to the surface channels to create apath through which the drugs can be delivered. For sub-surface channels,holes must be drilled from the surface of the substrate (the body of theimplant) to the sub-surface channels to create paths for drugs to bedelivered. (See FIG. 16). This drilling can occur prior to attaching theporous coating/surface or after the porous coating/surface is attached.If this drilling occurs after the porous coating/surface is attached,the holes will be created through the porous coating/surface and thesubstrate/body surface. (See FIG. 16).

Cement restrictors can also be used according to the present inventionto prevent cement from sealing over the drug delivery holes. The presentinvention can be applied to all types of total joint implants, such astotal hip components, total knee components, total shoulder components,and total elbow components.

With regard to enhancing bone ingrowth and combating resorbtion, bonegrowth stimulators can be injected intraoperatively or postoperativelyto enhance or speed bone ingrowth into porous material (i.e., porouscoatings or pads or surfaces on total joint components, on fusiondevices (i.e., spinal fusion devices), or on bone augmentationcomponents (i.e., tibial wedges)). These drugs could also be injectedmonths to years post-operatively, using a long-term implant according tothe present invention, to combat bone resorbtion due to such causes asstress-shielding, osteolysis, or bone metabolic disorders.

With regard to oncology, the implant of the present invention wouldsimilarly allow for delivery of drugs to some or all tissue surroundingthe implant. The implants of the present invention may be cemented. Thepresent invention provides a way to route the drugs around the regionsof cement and provides a way for preventing the cement from sealing overthe drug delivery holes.

The implants according to the present invention shown in FIGS. 17-19 arenon-permanent implants. Such implants can be trauma products, such asnails, plates, and external fixation devices. The non-permanent implantsof the present invention are not necessarily limited to these devices.The non-permanent implants of the present invention have a basicsimilarity with the short-term and long-term implants described above.Thus, structural features in FIGS. 17-19 corresponding to similarfeatures in FIG. 1 have reference characters raised by multiples of 100.Thus, similar to the short-term and long-term implants described above,the present invention further provides a non-permanent implant whichwould allow drugs to be delivered directly to the bone and surroundingtissue (or to any specific location). Reservoirs and/or channels in thenon-permanent implant according to the present invention would allow thedrugs to be delivered to the treatment site and could be refilled. Anail according to the present invention is shown in FIG. 17. A plateaccording to the present invention is shown in FIG. 18. An externalfixation device according to the present invention is shown in 19.

Nails are temporary, intramedullary devices. They are typically used totreat traumatic fracture. The risk of infection can be high especiallyin the case of open fractures. The present invention would allowantibiotics to be delivered to the bone surrounding the nail as apreventative or to treat an infection if one develops.

With regard to bone growth, in the case of fractures, there areinstances in which the delivery of bone growth stimulators directly tothe region of the fracture(s) would be beneficial. This is especiallytrue in difficult cases such as non-unions, bony defects, andosteotomies. The nail according to the present invention would allow forsuch delivery bone growth stimulators directly to the region of thefracture(s).

With regard to oncology, nails can be used to treat fractures associatedwith bone tumors. They can also be used to help prevent a fracture wherecancer has weakened bone. The nail according to the present inventionprovides for localized delivery of oncological drugs in the region oftumors which may improve results in slowing/halting tumor growth. Thisability for localized delivery provided by the nail according to thepresent invention may also lessen the need/dose of systemic drugs,resulting in fewer side effects.

FIG. 17 shows an orthopaedic nail 1232 implantable in the corporealbody. Structural features in FIG. 17 corresponding to similar featuresin prior figures have reference characters raised by multiples of 100.Nail 1232 includes a body 1244 defining a reservoir 1238 and a drugdelivery channel 1240 leading from drug reservoir 1238 to exteriorsurface 1246 of nail 1232. The present invention thus provides anorthopaedic nail 1232 with a drug delivery portion, which is similar tothat, for instance, for long-term implants, such as a femoral hipimplant (such as a hip stem). This design allows drugs to be delivereddirectly to all areas of the bone or to any specific location. (FIG.17). A device such as a port could be used to allow for post-operativeinjections of drugs into the nail 1232. This would allow for thedelivery of any number of drugs throughout treatment. Reservoirs 1238and/or channels 1240 in the nail 1232 would allow the drugs from theseinjections to be delivered over a time period from hours to weeks. Thus,upon filling reservoir 1238 with the therapeutic agent (either initiallyand/or as a refill), the therapeutic agent can move from the reservoir1238 to the treatment site via channels 1240. The drugs could bedelivered to all bone tissue surrounding the implant or only to specificlocations. All types of nails could utilize this technology, includingantegrade and retrograde versions of femoral, tibial, and humeral nails.

Orthopaedic plates treat many of the same indications as nails; however,plates are applied to the outside of the bone. Plates offer the sameopportunities for delivering drugs locally. Since nails areintramedullary, they can be used to deliver drugs, according to thepresent invention, primarily to the bone tissue. Since plates areapplied to the outside of the bone, they can be used to deliver drugs,according to the present invention, to both bone and soft tissues.Examples of potential soft tissue treatments benefited by localized drugdelivery include the enhancement of soft tissue ingrowth or healing, theprevention of infection by the delivery of antibiotics, and thetreatment of nearby soft tissue tumors with localized delivery ofoncological drugs.

FIG. 18 shows an orthopaedic plate 1332 that is implantable in acorporeal body. Structural features in FIG. 18 corresponding to similarfeatures in prior figures have reference characters raised by multiplesof 100. Plate 1332 includes a body 1344 defining a reservoir 1338 and adrug delivery channel 1340 leading from drug reservoir 1338 to exteriorsurface 1346 of plate 1332. Upon filling reservoir 1338 with thetherapeutic agent (either initially and/or as a refill), the therapeuticagent can move from the reservoir 1338 to the treatment site viachannels 1340.

Thus, the drug delivery portion of plate is similar to that fororthopaedic nails according to the present invention. Plate allows drugsto be delivered directly to the bone and surrounding tissue (or to anyspecific location). A device such as a port could be used to allow forpost-operative injections of drugs into plate. This would allow for thedelivery any number of drugs throughout treatment. Reservoirs 1338and/or channels 1340 in the plate implant 1332 allow the drugs fromthese injections to be delivered over a time-period from hours to weeks.The drugs could be delivered to all bone and soft tissue surrounding theplate implant 1332 or only to specific locations.

External fixation devices are temporary implants that are used tostabilize a fracture. These external fixation devices can be used fordays to months. External fixation devices typically include several pinsfixed in the bone and extending through the skin to a rigid plate, ring,rod, or similar stabilizing device. These devices carry the added riskof infection considering that the pins extend through the skin. Bacteriacan travel along the pins directly to the soft tissue and bone. Thepresent invention can be applied to external fixation devices. Thus,antibiotics or other anti-infective agents can be provided to the boneand soft tissue surrounding the pins. (FIG. 19). An external reservoircould be used to supply/pump antibiotics to the bone and soft tissue.

FIG. 19, for instance, shows an external fixation device 1432 accordingto the present invention which is a trauma device. Structural featuresin FIG. 19 corresponding to similar features in prior figures havereference characters raised by multiples of 100. External fixationdevice 1432 includes an implantable pin 1476, a sheath 1478 coupled withpin 1476, and a reservoir 1480 coupled with sheath 1478, pin 1476defining a plurality of channels 1440. More specifically, pin 1476includes a wall 1482 defining an inner spatial area 1484 and a pluralityof drug delivery channels 1440 or holes 1440. Connected to the outercircumference of the pin 1476 is sheath 1478, which can be coaxial withpin 1476. Sheath 1478 serves to prevent drugs from exiting that portionof the external fixation device 1432 which is outside of the skin 1434.To the right (as oriented on the page of FIG. 19) of the wall of skin1434 is space that is external to the corporeal body. Further, drugreservoir 1480 is attached to sheath 1478. Drug reservoir 1480 is shapedto allow attachment of the external fixation device 1432 to externalfixation rods and/or plates (not shown). The therapeutic agent movesfrom drug reservoir 1480 to the inner spatial area 1484 of pin 1476,through channels/holes 1440 in pin wall 1482, and to the treatment site.Thus, upon filling reservoir 1480 with the therapeutic agent (eitherinitially and/or as a refill), the therapeutic agent can move from thereservoir 1480 to the treatment site 1442 via inner spatial area 1484and channel(s) 1440.

Shortcomings of temporary bone cement implants used to treat infectionsare discussed above. An additional shortcoming includes the difficultyof delivering adequate quantities of therapeutic agents through suchimplants to bone due to lack of blood flow. FIGS. 20-27 provideorthopaedic drug delivery implants which address this shortcoming. Morespecifically, FIGS. 20-21 provide therapeutic agent delivery via aremovable and replaceable cartridge. Further, FIGS. 22-26 providetherapeutic agent delivery via leaching through an implant that ispartially or totally porous. Further, FIG. 27 provides a modifiedreservoir design. The designs shown in FIGS. 20-27 can be used inshort-term, long-term, or non-permanent orthopaedic implants. Structuralfeatures in FIGS. 20-27 corresponding to similar features in priorfigures have reference characters raised by multiples of 100.

FIGS. 20 and 21 show an orthopaedic implant system 1530 including anorthopaedic implant 1532 and a cartridge 1586. More specifically, FIG.20 shows cartridge 1586 inserted in implant 1532. FIG. 21, however,shows implant 1532 with cartridge 1586 removed. Implant 1532 is formedas, for example, a short-term femoral hip prosthetic implant 1532.Implant 1532 is implanted in corporeal body 1534. Implant 1532 isdefined by its body 1544. Body 1544 defines a reservoir 1538 and aplurality of channels 1540 running from the reservoir 1538 to theexterior surface 1546 of body 1544. Cartridge 1586 is inserted into andthus received by reservoir 1538, which serves as a housing for cartridge1586. Thus, reservoir 1538, as a housing for cartridge 1586, may beshaped to matingly accommodate and connect to cartridge 1586. Reservoir1538 can be generally cup-shaped and thus be open to exterior surface1546 (and thus reservoir 1538 can essentially be a blind hole inexterior surface 1546) so as to receive cartridge 1586. Cartridge 1586contains at least one therapeutic agent 1536, which is shown in brokenlines in FIG. 20. Cartridge 1586 is configured for releasing thetherapeutic agent 1536 (shown as a circle in cartridge 1586) intoreservoir 1538 and/or at least one channel 1540 such that thetherapeutic agent 1536 moves away from reservoir 1538 in at least onechannel 1540 and thus to exterior surface 1546 of body 1544. Cartridge1586 is removable from reservoir 1538 and is replaceable with anothercartridge 1586 after implant 1532 has been implanted in the corporealbody. The first cartridge 1586 is replaced when it is empty of thetherapeutic agent (or when it has otherwise released the desired amountof therapeutic agent from the first cartridge 1586). The secondcartridge 1586, which replaces the empty first cartridge 1586, is full(or has the desired amount of therapeutic agent therein) of therapeuticagent when it is inserted into reservoir 1538 and thereby replaces firstcartridge 1586. Thus, the refilling of reservoir 1538 in system 1530occurs by replacing first cartridge 1586 with a second cartridge 1586.

Thus, system 1530 can have implant body 1544 and a replaceable portionor cartridge 1586. (FIGS. 20-21). Replaceable cartridge 1586, as stated,contains therapeutics. Upon implantation, the surgeon can decide withwhat therapeutics to fill cartridge 1586. Over time, cartridge 1586 canbe replaced with a new cartridge 1586 filled with the same therapeuticas before or a different therapeutic. Ideally, cartridge replacementwould occur as a minor outpatient procedure.

The replaceable cartridge may be optionally formed relative to theimplant. As a first option, the cartridge may be considered a distinctdevice relative to the implant but which can be directly attached to theimplant, as shown in FIG. 20. As a second option, the cartridge may beconsidered a portion of the implant which can be detached from theimplant body. As a third option, the cartridge may be a secondreplaceable implant located within the patient body away from the firstimplant (i.e., the femoral hip implant) but connected to the firstimplant, such as via a catheter. As a fourth option, the cartridge maybe a device that is situated external to the patient body, while theimplant (i.e., the femoral hip implant) is implanted in the patientbody.

FIGS. 22-26 show implants that are partially or totally porous tofacilitate therapeutic agent delivery via leaching through therespective implant. In much the same manner of powder metallurgybearings that are self-lubricating, therapeutic agents may be deliveredto the patient body from an implant that is partially or totally porous.(FIGS. 22-26). Therapeutics will leach from the porous portions of theimplant to the body. Such implants may also contain drug deliverychannels, reservoirs, and the various ways of recharging therapeutics aspreviously discussed herein. FIGS. 22 and 23 each shows a femoral hipprosthetic implant 1632 in which the entire body 1644 of the implant1632 is porous to facilitate leaching of therapeutic agents therefrom.Pores are labeled as 1690. The implant 1632 of FIG. 22, however, doesnot include in addition thereto a drug reservoir or drug deliverychannels. Thus, the therapeutic agent is delivered via the pores 1690 ofimplant 1632 to the treatment site, which can be within or outside ofthe pores 1690. By contrast, FIG. 23 shows a drug reservoir 1638 anddrug delivery channels 1640 embedded in or defined by the body 1644 ofthe implant 1632. Thus, upon filling reservoir 1638 with the therapeuticagent (either initially and/or as a refill), the therapeutic agent canmove from the reservoir 1638 to the treatment site via channels 1640.FIGS. 24-26 each shows a femoral hip prosthetic implant 1732 in which aportion of the body 1744 of the implant 1732 is porous to facilitateleaching of therapeutic agents therefrom. The porous portion of body1744 is labeled as 1790. The implant 1732 of FIG. 24, however, does notinclude in addition thereto a drug reservoir or drug delivery channels.Thus, the therapeutic agent can be delivered via the porous portion 1790to the treatment site, which can be within or outside of the porousportion 1790. By contrast, the implants 1732 of FIGS. 25 and 26 doinclude in addition thereto a drug reservoir 1738 and drug deliverychannels 1740. FIG. 25 shows the reservoir 1738 embedded in or definedby the porous portion 1790 of the body 1744 of the implant 1732 and drugdelivery channels 1740 at least partially embedded in or defined by theporous portion 1790 of the body 1744 of the implant 1732. Thus, uponfilling reservoir 1738 with the therapeutic agent (either initiallyand/or as a refill), the therapeutic agent can move from the reservoir1738 to the treatment site (which can be either within or outside of theporous portion 1790) via channels 1740. FIG. 26 shows that the reservoir1738 is not located in the porous portion 1790 and shows the drugdelivery channels 1740 at least in part leading to the porous portion1790. Thus, upon filling reservoir 1738 with the therapeutic agent(either initially and/or as a refill), the therapeutic agent can movefrom the reservoir 1738 to the treatment site (which can be eitherwithin or outside of the porous portion 1790) via channels 1740.

FIG. 27 shows an orthopaedic implant system 1830 with a femoral hipprosthetic implant 1832 and a sponge-like or spongy material or element1892. Similar to the implants discussed above, the body 1844 of theimplant 1832 defines a drug reservoir 1838 and drug delivery channels1840 leading from the reservoir 1838 to the exterior surface 1846 of thebody 1844. The reservoir 1838 contains or houses the spongy element1892. The purpose of this material is to control dispersion of thetherapeutic agents from the reservoir 1838 into the drug deliverychannels 1840, to keep bone and tissue from growing into and filling thereservoir 1838, and/or to stiffen the implant 1832. Upon fillingreservoir 1838 with the therapeutic agent (either initially and/or as arefill) and having positioned sponge-like material 1892 in reservoir1838, the therapeutic agent can move from the reservoir 1838 (and thusalso from spongy element 1892) to the treatment site via channels 1840.Depending upon the outcome desired, the material of the sponge-likeelement 1892 can be a number of possibilities. For example, if thesponge 1892 is to remain in reservoir 1838 for a long time, then aPolyvinyl Alcohol (PVA) or Ivalon sponge, for example, can be used. Onthe other hand, if the sponge 1892 is to last a shorter amount of time,then a collagen based material (i.e., Instat, by Johnson and Johnson,for example) or a gelatin sponge (i.e., Gelfoam, by Pfizer, forexample), for example, can be used. These examples of the sponge 1892are provided by way of example, and not by way of limitation.

Any of the devices according to the present invention described abovecan include a single or multiple attachment features (such asconnections for catheters or ports) and a single or multiple sets ofreservoirs and/or channels. The same therapeutic agent can be used inall reservoirs/channels, or several therapeutic agents can be used atone time. Separate reservoirs/channels allow each of the therapeuticagents to be delivered to a specific location on the implant, ifdesired.

Any of the internal (implanted) devices according to the presentinvention described above can include an internal reservoir (containedwithin the implant) in conjunction with delivery channels/paths to allowfor short- and/or long-term delivery of the therapeutic agents. If aninternal reservoir does not exist, the implant can contain deliverychannels/paths to allow for the dispersion of the therapeutic agent.

According to the present invention, therapeutic agents can be introducedinto the delivery channels/paths and/or implant reservoir of the implantof the present invention by one or more of the following ways:

-   -   a. Direct interface between a delivery vessel (such as a        hypodermic syringe).    -   b. Direct attachment of a drug pump, external reservoir        (external to the implant, but can be located internally or        externally to the patient), and/or port to the implant; that is,        a drug pump, external reservoir, and/or port can be attached        directly to the implant. A catheter can be, but is not        necessarily, located between the drug pump, external reservoir,        and/or port and the implant. The therapeutic agent is then        introduced into one of these intermediary devices by, for        example, a hypodermic syringe. The therapeutic agent is then        transferred to the implant delivery channels/paths and/or        implant reservoir.    -   c. A drug pump, reservoir, and/or port can be implanted in the        body in another location remote to the implant and/or can be        connected to the implant by, for example, a delivery tube or        catheter. FIG. 28 shows schematically this option for an        orthopaedic implant system. According to system 1930, a        reservoir 1994, a pump 1995, and a port 1996 are implanted under        the skin of a patient body 1934 remote from implant 1932 and are        shown connected via an implanted catheter 1998 to the reservoir        1938 of the implant 1932. The reservoir 1994, pump 1995, and        port 1996 are thereby configured for delivering the therapeutic        agent (shown by arrow 1936, which also shows the direction of        travel of the therapeutic agent) from the reservoir 1994 to the        treatment site 1942 via the implant 1932. Stated another way,        the pump 1995 and port 1996 can cooperate with the reservoir        1938 to deliver the therapeutic agent 1936 via the catheter 1998        to the reservoir 1938 defined by the body of the implant 1932.        The body of implant 1932 can define channels, either sub-surface        or surface channels, running from reservoir 1938 to the exterior        surface of implant 1932. The implant 1932 is an orthopaedic        implant, such as a prosthesis, a nail, a plate, or an implanted        pin of an external fixation device.    -   d. A drug pump, reservoir, and/or port can be located external        to the body and connected to the implant by, for example, a        delivery tube or catheter. The main difference between the        example of this subparagraph and the example of subparagraph c        of this paragraph is that the catheter runs from one location        inside the body to another location inside the body in the        example of subparagraph c of this paragraph, while the catheter        runs from outside of the body to the implant inside the body in        the example of this subparagraph. FIG. 29 shows schematically        this option for an orthopaedic implant system. According to        system 2030, a reservoir 2094, a pump 2095, and a port 2096 are        not implanted under the skin of a patient body 2034 but are        shown connected to the reservoir 2038 of the implant 2032 by a        transcutaneous (passing, entering, or made by penetration        through the skin) catheter 2098. The reservoir 2094, pump 2095,        and port 2096 are thereby configured for delivering the        therapeutic agent (shown by arrow 2036, which also shows the        direction of travel of the therapeutic agent) from the reservoir        2094 to the treatment site 2042 via the implant 2032. Stated        another way, the pump 2095 and port 2096 can cooperate with the        reservoir 2094 to deliver the therapeutic agent 2036 via the        catheter 2098 to the reservoir 2038 defined by the body of the        implant 2032. The body of implant 2032 can define channels,        either sub-surface or surface channels, running from reservoir        2038 to the exterior surface of implant 2032. The implant 2032        is an orthopaedic implant, such as a prosthesis, a nail, a        plate, or an implanted pin of an external fixation device.    -   e. A catheter runs from outside the body to the implant inside        the body but would not include a pump, a reservoir, or a port        being attached to the outside end of the catheter (the outside        end being the end opposite the end which is attached to the        implant).

The orthopaedic implants of the present invention can be applied inconjunction with any currently available designs, including porouscoatings, and can also be used in conjunction with cemented implants.

The present invention further provides a method of using an orthopaedicimplant system, such as system 30. The method includes the steps of:implanting an orthopaedic implant 32 at a selected location within acorporeal body 34, implant 32 including a reservoir 38 and a pluralityof channels 40; receiving at least one therapeutic agent 36 in reservoir38; conveying at least one therapeutic agent 36 from reservoir 38 to atreatment site 42 relative to corporeal body 34 via channels 40; anddelivering at least one therapeutic agent 42 to corporeal body 34. Asdiscussed above, the implant according to the present invention is aprosthesis, a nail, a plate, or an external fixation device with animplanted pin. Implant 32 includes a body 44 which is implanted at theselected location, body 44 defining reservoir 38 and channels 40 andincluding an exterior surface 46, channels 40 fluidly communicatingreservoir 38 with exterior surface 46 and thereby conveying therapeuticagent 36 from reservoir 38 to exterior surface 46. The method caninclude attaching a porous surface 1154 to exterior surface 1146, poroussurface 1154 receiving bone and/or tissue ingrowth 1156 therein, poroussurface 1154 including a first side 1164 attached to exterior surface1146 and a second side 1166 opposing first side 1164, porous surface1154 including a through-hole 1168 running from first side 1164 tosecond side 1166, through-hole 1168 communicating at least onetherapeutic agent 1136 from first side 1164 to second side 1166 andthereby communicating at least one therapeutic agent 1136 to treatmentsite 1142. Exterior surface 1146 can define a surface channel 1170,surface channel 1170 being in communication with and cooperating with atleast one channel 1140 and at least one through-hole 1168 and therebyproviding at least one therapeutic agent 1136 from reservoir 1138 totreatment site 1142. At least one channel 40 can be a sub-surfacechannel 1172, sub-surface channel 1172 and through-hole 1168 beingaligned with and cooperating with one another and thereby providing atleast one therapeutic agent 1136 from reservoir 1138 to treatment site1142. The method can include implanting a second reservoir 1994, a pump1995, and/or a port 1996 in corporeal body 1934 remote from implant1932, connecting second reservoir 1994, pump 1995, and/or port 1996 toreservoir 1938 of implant 1932 by at least one catheter 1998 implantedin corporeal body 1934, and delivering at least one therapeutic agent1936 to treatment site 1942 via implant 1932, catheter 1998, and secondreservoir 1994, pump 1995, and/or port 1996. The method can includeproviding a second reservoir 2094, a pump 2095, and/or a port 2096 whichis not implanted in corporeal body 2034, connecting second reservoir2094, pump 2095, and/or port 2096 to reservoir 2038 of implant 2032 byat least one transcutaneous catheter 2098, and delivering at least onetherapeutic agent 2036 to treatment site 2042 via implant 2032, catheter2098, and second reservoir 2094, pump 2095, and/or port 2096. The methodcan include inserting a cartridge 1586 into reservoir 1538, cartridge1586 containing at least one therapeutic agent 1536 and releasing atleast one therapeutic agent 1536 into reservoir 1538 and/or at least onechannel 1540 such that at least one therapeutic agent 1536 moves awayfrom reservoir 1538 in at least one channel 1540, removing cartridge1586 from reservoir 1538 after implant 1532 has been implanted incorporeal body 1534, and replacing cartridge 1586 with another cartridge1586 after implant 1532 has been implanted in corporeal body 1534. Themethod can include providing a spongy element 1892, reservoir 1838containing spongy element 1892. Body 1644, 1744 of implant 1632, 1732can be partially or completely porous. External fixation device 1432 caninclude implantable pin 1476, a sheath 1478 coupled with pin 1476, andreservoir 1480 coupled with sheath 1478, pin 1476 defining a pluralityof channels 1440. Implant may include only one reservoir. The method caninclude refilling reservoir 38 with at least one therapeutic agent 36after implant 32 has been implanted in corporeal body 34. The method caninclude delivering a plurality of therapeutic agents 36 to corporealbody 34 via reservoir 38 and channels 40 of implant 32.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

What is claimed is:
 1. An orthopaedic implant system, comprising: anexternal fixation device including an implantable pin, a sheath coupledwith said pin, a reservoir coupled with said sheath, and a plurality ofchannels, said external fixation device being implantable at a selectedlocation within a corporeal body and configured for delivering at leastone therapeutic agent to said corporeal body, said reservoir configuredfor receiving said at least one therapeutic agent, said plurality ofchannels configured for conveying said at least one therapeutic agentfrom said reservoir to a treatment site relative to said corporeal body,said pin defining said plurality of channels.
 2. The orthopaedic implantsystem of claim 1, wherein said pin defines said reservoir and includesan exterior surface, said plurality of channels fluidly communicatingsaid reservoir with said exterior surface and thereby being configuredfor conveying said at least one therapeutic agent from said reservoir tosaid exterior surface.
 3. The orthopaedic implant system of claim 2,further including a porous surface attached to said exterior surface,said porous surface configured for receiving at least one of bone andtissue ingrowth therein, said porous surface including a first sideattached to said exterior surface and a second side opposing said firstside, said porous surface including a through-hole running from saidfirst side to said second side, said through-hole configured forcommunicating said at least one therapeutic agent from said first sideto said second side and thereby for communicating said at least onetherapeutic agent to said treatment site.
 4. The orthopaedic implantsystem of claim 3, further including a surface channel defined by saidexterior surface, said surface channel being in communication with andcooperating with one said channel and said through-hole to provide saidat least one therapeutic agent from said reservoir to said treatmentsite.
 5. The orthopaedic implant system of claim 3, wherein at least oneof said channels is a sub-surface channel, said sub-surface channel andsaid through-hole being aligned with and cooperating with one another toprovide said at least one therapeutic agent from said reservoir to saidtreatment site.
 6. The orthopaedic implant system of claim 2, furtherincluding at least one of a second reservoir, a pump, and a portimplantable in said corporeal body remote from said external fixationdevice and connected to said reservoir of said external fixation deviceby at least one catheter implantable in said corporeal body and therebyconfigured for delivering said at least one therapeutic agent to saidtreatment site via said external fixation device.
 7. The orthopaedicimplant system of claim 2, further including at least one of a secondreservoir, a pump, and a port not implantable in said corporeal body butwhich is connected to said reservoir of said external fixation device byat least one transcutaneous catheter and which is thereby configured fordelivering said at least one therapeutic agent to said treatment sitevia said external fixation device.
 8. The orthopaedic implant system ofclaim 2, further including a cartridge inserted into said reservoir,said cartridge containing said at least one therapeutic agent and beingconfigured for releasing said at least one therapeutic agent into atleast one of said reservoir and at least one of said channels such thatsaid at least one therapeutic agent moves away from said reservoir insaid at least one channel, said cartridge being removable from saidreservoir and replaceable with another cartridge after said externalfixation device has been implanted in said corporeal body.
 9. Theorthopaedic implant system of claim 2, wherein said pin is one ofpartially porous and completely porous.
 10. The orthopaedic implantsystem of claim 2, wherein said implant includes only one saidreservoir.
 11. The orthopaedic implant system of claim 2, wherein saidreservoir is configured for being refilled with said at least onetherapeutic agent after said external fixation device has been implantedin said corporeal body.
 12. The orthopaedic implant system of claim 2,wherein said external fixation device is configured for delivering aplurality of therapeutic agents to said corporeal body via saidreservoir and said plurality of channels.
 13. The orthopaedic implantsystem of claim 1, further including a spongy element, said reservoircontaining said spongy element.
 14. A method of using an orthopaedicimplant system, said method comprising the steps of: implanting anorthopaedic implant at a selected location within a corporeal body, saidimplant including an implantable pin, a sheath coupled with said pin, areservoir coupled with said sheath, and a plurality of channels, saidpin defining said plurality of channels, said pin being implanted atleast partially within the corporeal body and said sheath and saidreservoir residing at least partially outside the corporeal body whensaid pin is implanted within the corporeal body; receiving at least onetherapeutic agent in said reservoir; conveying said at least onetherapeutic agent from said reservoir to a treatment site relative tosaid corporeal body via said plurality of channels; and delivering saidat least one therapeutic agent to said corporeal body.
 15. The method ofclaim 14, wherein said pin defines said reservoir and includes anexterior surface, said plurality of channels fluidly communicating saidreservoir with said exterior surface and thereby conveying said at leastone therapeutic agent from said reservoir to said exterior surface. 16.The method of claim 15, further including attaching a porous surface tosaid exterior surface, said porous surface receiving at least one ofbone and tissue ingrowth therein, said porous surface including a firstside attached to said exterior surface and a second side opposing saidfirst side, said porous surface including a through-hole running fromsaid first side to said second side, said through-hole communicatingsaid at least one therapeutic agent from said first side to said secondside and thereby communicating said at least one therapeutic agent tosaid treatment site.
 17. The method of claim 14, further includingrefilling said reservoir with said at least one therapeutic agent. 18.The method of claim 14, further including implanting at least one of asecond reservoir, a pump, and a port in said corporeal body remote fromsaid implant, connecting at least one of said second reservoir, saidpump, and said port to said reservoir of said implant by at least onecatheter implanted in said corporeal body, and delivering said at leastone therapeutic agent to said treatment site via said implant, saidcatheter, and at least one of said second reservoir, said pump, and saidport.
 19. The method of claim 14, further including providing at leastone of a second reservoir, a pump, and a port which is not implanted insaid corporeal body, connecting at least one of said second reservoir,said pump, and said port to said reservoir of said implant by at leastone transcutaneous catheter, and delivering said at least onetherapeutic agent to said treatment site via said implant, saidcatheter, and at least one of said second reservoir, said pump, and saidport.
 20. The method of claim 14, further including inserting acartridge into said reservoir, said cartridge containing said at leastone therapeutic agent and releasing said at least one therapeutic agentinto at least one of said reservoir and at least one of said channelssuch that said at least one therapeutic agent moves away from saidreservoir in said at least one channel, removing said cartridge fromsaid reservoir after said implant has been implanted in said corporealbody, and replacing said cartridge with another cartridge after saidimplant has been implanted in said corporeal body.